1. Field of the Invention
The present invention relates generally to the field of dental implants and in particular to a system providing a tooth analogue and a gingival tissue healing cap which results in a restoration having tissue-implant profiles similar to that of a natural tooth and its surrounding gingiva. The present invention also relates to fitting a tooth with a temporary crown and final prosthesis after the initial implant structure has been inserted and the surrounding tissue has healed. More particularly, the present invention relates to the field of anatomical restoration dental implant systems with interlockable elliptical healing cap and abutment.
2. Description of the Prior Art
Many systems have been proposed for rigidly fixing metal or ceramic materials to the alveolus of a human mandible or maxilla in an effort to provide a long term replacement for lost teeth. Early systems were successful for only limited periods of time and were eventually rejected as foreign bodies. Later systems, as described by U.S. Pat. Nos. 3,589,011 to Sneer, 3,797,113 to Brainin, 3,979,828 to Taylor, 4,324,550 to Reuther et al., and 4,416,679 to Mozsary et al., have proven to offer long term success by providing rigid anchorage in the supporting bone. Intraoral restoration of such ossointegrated devices has been accomplished with many different systems that modified the original attempts. Such modifications have been described in U.S. Pate. Nos. 4,780,080 to Harras, 4,713,003 to Symington et al., and 4,657,510 to Gittlemen. However, these restorative systems have required biologic and aesthetic compromises. The interface between an implant and its surrounding gingival tissue is often insufficiently close to prevent food and bacteria from entering this area. Such foreign matter can cause chronic infection and bone loss, resulting in eventual loss of the implant. Implants in current use have a round root form dimensionally different from that of a normal tooth root morphology. This makes aesthetic restoration difficult and impedes the development of a natural soft gingival tissue contour.
The inventor and applicant of the present invention has been practicing anatomical restoration dental implant surgery for many years and is the patentee of a series of U.S. patents related to anatomical restoration dental implant systems. U.S. Pat. No. 5,073,111 issued to Daftary on Dec. 17, 1991 (hereafter "the '111 patent") disclosed an anatomical restoration dental implant system. Shown in FIGS. 1 and 2, the '111 patent disclosed an anatomical restoration dental implant system for implanting a tooth analogue 102 in the alveolus of the jawbone 104. The system comprises an implantable fixture 106 implanted through opened gingival tissue 108 into the alveolus of the jaw bone 104. A cover screw (not shown) is used for sealing the hollow of the implant fixture 106 during the time the jaw bone 104 is growing about the implant fixture 106. After osseointegration of the implant fixture 106, the gingiva 108 is reopened and the cover screw is removed and replaced by a healing cap 110. The healing cap 110 provides a predetermined contour to the re-healing gingival tissue 108. After the re-opened gingival tissue 108 has healed about the healing cap 110, the healing cap 110 is removed and replaced with an abutment 112 having the same contour as that of the healing cap 110. Having the same contour permits the abutment 112 to tightly fit the healed opening in the gingival tissue 108 upon engagement of the abutment 112 with the implant fixture 106. The abutment 112 is removably affixed to the implant fixture 106 by a screw 114. Thereafter the tooth analogue 102 is releasibly engagable with the abutment 112 by a small holding screw 116.
U.S. Pat. No. 5,035,619 issued to Daftary on Jul. 30, 1991 (hereafter "the '619 patent") disclosed an anatomical restoration dental implant system with improved healing cap and abutment. U.S. Pat. No. 5,145,372 issued to Daftary et al. on Sep. 8, 1992 (hereafter "the '372 patent") disclosed an anatomical restoration dental implant system with reinforced healing cap and abutment. The '619 patent introduced an assembly of a two-piece healing cap and a matching abutment for improving the healing process of the gingival tissue 108, and the '372 patent provided a reinforced assembly of the two-piece healing cap and the matching abutment. The two-piece healing cap configurations are designed to prevent the unnecessary damage or delay to the healing of the gingival tissues. However, it is always desirable to improve the anatomical restoration dental implant system so that it can provide a contour more nearly approximating that of a natural tooth and its surrounding tissue, and an implant root and gingival tissue interface that enhances the resistance to bacterial infection.
In addition, under some special circumstances an angled abutment member is needed for supporting a tooth analogue. A typical one of these special circumstances is that the part of a patient's jaw bone directly underneath the tooth is damaged, so that the dental implant fixture has to be implanted on an adjacent part of the patient's jaw bone. Under such a circumstance, the exposed surface of the dental implant fixture is often misaligned. After a healing cap is secured to the implant fixture, the axis normal to the top surface of the healing cap is often not aligned with the axis of the tooth. In this situation, an angled abutment member is needed. Therefore, it is also desirable to have an angled abutment assembly which can support a tooth analogue on the healing cap in such misaligned situation.